This invention relates to a corner joint for positively locking the corners of horizontal or lateral rail members and upright members forming part of a modular assembly constructed of interconnected horizontal and upright rail members for supporting shelving, side wall members, doors and such like components.
Modular assemblies of the type formed by interconnecting upright rails with horizontal crossbeams or rails are well known. In various designs the rails are provided separately and the user is instructed as to the manner of assembling the rails to form a modular assembly. When formed the modular assembly creates an open frame defining box-like modules for supporting shelving, side walls, doors and other such like components. The modular assembly may be formed in various configurations with the end product having the same function, that is supporting components. The rail members may be interconnected or joined by various constructions. One common construction is that of interconnected forks of varying designs. In some instances the forks are secured by an adhesive or screws, nut and bolts, or the like. Other designs provide wedging elements for securing the joints in place. Where the joints at the rail interconnections are not positively secured by adhesives or other fasteners, there is a tendency for the joints to loosen or come apart when any force is brought to bear on the rails in a direction of separating the joints. The use of wedging elements to provide a positive lock on the interconnecting joints affords satisfactory positive locking but requires the need of additional elements creating an increased expense as well as complicating the overall structure. Virtually all of the heretofore known modular assembly designs are open to becoming disjointed at their corners or require additional elements or adhesives to form positive locks for preventing disjointing of the rail members.